Multipurpose working, load carrying and camping platform structure

ABSTRACT

This patent describes a platform structure, which can be used either as a stand-alone unit, or as part of the body of a wheeled vehicle such as a trailer. As part of the body of a trailer its multipurpose feature allows the trailer to be easily converted into different modes of usage including: an extended platform, a flat-bed trailer with side walls, an open-top utility box trailer, or a compact highway trailer. The highway trailer, with a compactly collapsed body equipped with a cargo-rack, is intended to offer the best possible towing performance at highway speed. The cargo-rack has a screen enclosure for the containment of small or loose cargo items. When used as a stationary platform, said structure has a center portion with adjustable leg assemblies that can support and level the entire structure above the ground. Side sections are cantilevered on opposite sides of the center portion to form extensions to the main platform area. Fastening means for the erection of a camping tent on said platform are also disclosed. The side sections can also be firmly erected in an upright position to form side walls of an open ended utility trailer. Here the end sections can be easily attached to convert the latter into an open-top utility box trailer.

TECHNICAL FIELD

This invention relates to a multipurpose structure for use as astand-alone utility platform that can be supported and levelled abovethe ground, or as a load-carrying platform on a wheeled vehicle such astrailer or pickup truck. Said structure is convertible between differentmodes of usage, including: an extended platform, an open-ended U-shapedassembly with flatbed and sidewalls, an open-top utility container, or acompactly collapsed structure with a cargo carrying rack.

Although the article of the present invention can be used as astand-alone structure removably attachable to a wheeled vehicle to becarried by the latter, for descriptive purposes in the followingdisclosure we mainly refer to said structure as forming an integral partof a trailer.

BACKGROUND OF THE INVENTION

Many previous patents teach the art of the collapsible trailer'sconstruction, which allows the trailers to be reduced to a more compactnon-used shape for stowage or for expanding the trailer body in order tocarry a larger or longer load on the flatbed area. When used on thehighway, these trailers are still too bulky and as a result theyobstruct the driver's rear view, they do not offer fuel economy or thesafest possible towing performance (e.g., FR 1.081.030; U.S. Pat. No.2,557,347; U.S. Pat. No. 3,715,141).

Most of the structures from prior arts are confined to one specificpurpose where, in the majority of cases, they would be used as a camper(e.g. U.S. Pat. No. 5,988,731; U.S. Pat. No. 4,198,996). Such single usestructures failed to attract the majority of consumers who find it hardto justify the price and storage space required for owning such device.The above comment is also applicable to each of the many interchangeabletransportation apparatuses that one can attached to a wheeled chassis asdisclosed in U.S. Pat. No. 3,524,659.

Many prior arts (e.g. U.S. Pat. No. 5,080,426)offer an expandable designwhere a large top or cover section of the trailer is folded out and thensupported on the ground independent of the main body. Such designsrequire a flat campground surface for proper erection, demanding moreskill from users. A challenging campground would have uneven surfaces,unleveled surfaces or surfaces interspersed with small rocks and/orbushes. In any of these cases, it would be impossible to set up campersas taught by the above prior arts or to erect conventional tents on theground without first preparing the surface.

Very often tents are custom fitted to the trailers and are erected upwith an unfolding or raising up of different parts of the trailer (e.g.,U.S. Pat. No. 5,375,902). The prior art does not teach a type of trailerconstruction that can be used with any standard tent design; this wouldconveniently complement the need of tent owners.

Many patents (FR 1.081.030; UK 2 035 915; U.S. Pat. No. 3,715,141)disclose a platform construction whereby side sections are partiallysupported from the ground and require additional adjustment from that ofthe center portion during each set up. The concepts presented in U.S.Pat. No. 2,557,347 use stakes and receiving pockets and that of FR1.315.737 use a larger trailer chassis than the usable flatbed surfaceas a means to support the folded-out sidewalls. Such assemblies do notprovide a solid stand-alone platform, they have limited load-carryingcapacity on the extended sidewalls or cannot be deployed quickly fromone configuration to the other.

There is no prior art that teaches the construction of a convertibletrailer having side sections that can be quickly raised from ahorizontal position and be held rigidly in an upright position relativeto the flatbed area to form an open ended U-shaped utility trailer. Suchconfiguration is very useful for the transportation of long articlessuch as lumbers, canoe, etc.

DISCLOSURE OF THE INVENTION

It is, therefore, a principal object of the present invention to providea multipurpose trailer which can be easily and quickly converted betweendifferent modes of usage: a working or camping platform, a U-shapedtrailer with flatbed and rigid sidewalls, an open-top utility boxtrailer, or a compact cargo-rack trailer. The versatility of the currentinvention will justify the cost and space requirements involved inowning such a trailer.

It is another object of the present invention to provide amaintenance-free camper that offers instead, an extended campingplatform that can be utilized with any standard tent design. This isintended to make tent usage more functional and practical, to offer alow cost alternative to owning a camper, and to provide a complementaryproduct for tent owners.

It is still another object of the present invention to provide a compacttrailer for highway use. Having the most compact body cross-sectionalarea, this trailer offers a minimal frontal draft for highest fuelefficiency, does not obstruct the driver's field of vision through rearview mirrors and is the least affected by lateral wind. This insures theeasiest and safest highway towing performance. The other modes of usagepresent a larger trailer body but are only required for hauling bulkierloads at relatively slower speeds.

It is a further object of the present invention to reduce the cost ofsuch a multipurpose trailer by minimizing the number of components. Thisis achieved through a judicious design of the many components of thetrailer, having them perform different tasks during different modes ofusage.

Furthermore, it is another object of the present invention to provide acargo-rack on a wheeled vehicle installed at a much lower deck elevationcompared to racks normally equipped on a car roof. This tremendouslyfacilitates the loading and unloading of cargo items.

Many other objects will in part be obvious and in part be describedhereinafter.

The main structure of the present invention comprises a center portion,which offers a main flatbed area, and side sections that areconfigurable into different positions. Said center portion is firmlyerected on the ground by means of four adjustable post assemblies whichextend downward at the four corners of said flatbed area. Said postsfirmly engage the ground's surface to support and level said centerportion in a stationary and levelled plane above the ground.

Side sections are pivotally connected on opposite sides of said centerportion by multiple hinges having pivot axes parallel to thelongitudinal edge of said center portion. These hinges located near theupper edges allow the side sections to be unfolded to a position wheretheir surfaces lie in a coplanar relationship with the top surface ofsaid center portion. In this position the bottom edges of the sidesections are supported by a plurality of vertical load bearing surfacesdisposed on the connected sides of the center portion. Side sections aretherefore fully cantilevered from the center portion, forming extensionson both sides of the main flatbed area.

This type of extended platform is very easy and quick to set up on anyground condition, side sections do not need to be supported from theground, thus no additional adjustment is required. The platform can beused for working or camping. For example, when used as a platform forthe erection of a camping tent, it offers many benefits that include thefollowing:

A platform that can accommodate any stand-alone standard tent design,offering a flat surface for the sleeping comfort of tent usersindependent of the campground condition.

Preventing the ingress of water, insects, or reptiles into the tentliving area.

Isolating of the tent floor from ground's surface humidity and dampness.

Eliminating the need for preparation of the campground surface under thetent platform.

Fastening means are provided for removably erecting any standard tentdesign on the platform. These allow a quick erection and removal of atent without disturbance to the trailer for the other modes of usage. Asa result, provision can also be made for erecting many different tentson the same trailer platform, thus allowing the greatest flexibility tousers.

When the trailer is used for carrying a load, center posts on theadjustable post assemblies are retracted upwardly away from the ground.In this movement the upper end portions of said posts are caused toengage with holding rings located at forward and rear ends and nearfreely swinging side of the hingedly connected side section. Thisprovides a releasable holding means to hold said side sections in agenerally upright position forming an open-ended U-shaped trailer withflatbed and sidewalls for the transportation of elongated articles suchas lumber, ladder, canoes, etc.

In another utility mode, end sections are slidably attached at oppositeends of the trailer to form an open-top utility box trailer for thecontainment and transportation of comminuted materials such as sand,garden soil, etc. A cover may be added to fully enclose the utility boxtrailer.

During highway use, the side sections are compactly folded and securelyheld down on top of said center portion to offer the lowest possibletrailer profile. A cargo rack is provided on top surfaces of the foldedpanels for the transportation of general cargo, such as luggage for ahighway trip. An enclosure is also included on the rack for the secureholding and locking of loose or small articles such as hand tools orcamping accessories.

The cargo-carrying feature of the rack can also be used in other foldedpositions of the side sections. For example, it is a place where gardentools are securable while the trailer is used for transporting gardeningmaterials.

Moreover, the racks are designed to stiffen the side sections andprovide strength and load handling capacity, allowing side sections tobe used as cantilevered platform extensions, this will be explainedlater in the description of the preferred embodiment of the invention.The resulting high bending stiffness of the side sections also allowsfor them to be supported only at the front and back ends. This sparesthe middle section from any disturbances, and maximizes the usable flatplatform surface area.

The preferred embodiment is that of the body structure of a trailer,however as aforementioned, the present invention can be used as astand-alone unit and can be removably attached to and be carried by awheeled vehicle such as a trailer or pickup truck. Once on site it canbe set up, firmly anchored, supported and levelled on the ground. Thewheeled vehicle can then be detached for other uses.

In another alternative the structure can also form an integral part ofthe body of another type of wheeled vehicle such as a pickup truck. Thisis where it would replace the cargo tub on the chassis of said vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric rear view of the structure of the presentinvention in its extended platform mode of usage, it is in use with atent shown in phantom lines for camping purpose.

FIG. 2 is an isometric front view of the present invention configuredinto a U-shaped trailer with flatbed and sidewalls, carrying a load oflumber shown in phantom lines.

FIG. 3 is an isometric front view of the inventive trailer in itsopen-top utility box configuration, containing a load of top soil andtransporting a shovel shown in phantom lines.

FIG. 4 is an isometric front view of the inventive trailer in itscompactly collapsed body configuration intended for highway use.

FIG. 5 is a side view of the inventive trailer in its highway useconfiguration carrying a bicycle and being towed behind a small car,both shown in phantom lines.

FIG. 6 is an enlarged isometric view illustrating the technique used toanchor a tent on the camping platform of the present invention.

FIG. 7 is an enlarged isometric view of a partial enclosure equipped onthe cargo-rack of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, the structure is shown converted betweendifferent modes of usage: an extended platform in FIG. 1, a U-shapedtrailer with flatbed and sidewalls in FIG. 2, an open-top bulk loadcontainer in FIG. 3, or a compact cargo-rack trailer in FIGS. 4 and 5.

As shown in FIG. 1, the structure comprises a center portion 10 that hasa flat surface with a length and a width that defines a flatbed area 11.Four adjustable post assemblies 16 are solidly mounted at the fourcorners of said flatbed area. Each of said adjustable post assembliescomprises a center post 17 slidably adjusted in the axial directioninside a sleeve 19. Said center posts can be extended downward to firmlyengage the ground's surface to support and level said center portion ina stationary and levelled plane above the ground. Said sleeve 19 has avariable radius portion 20 with clamping means 21 that reduces itsradius to firmly grip and hold said center post in a given axialposition. End foot 22 has threaded stem 23 that engages matchingthreaded hole disposed at the end of said center post, to allow fineradjustment of the vertical elevation of the platform when needed.

A series of holes 18 drilled at preset distances from each other alongthe length of the center post for the insertion of the safety pin 24. Acorresponding retaining pin 25 keeps the safety pin in place on thecenter post. In this mode of usage, the safety pin 24 is used to limitthe vertical drop of the platform should the clamping means 21 loose itsgrip on the center post 17. For this purpose said safety pin is insertedthrough the closest holes 18 that are accessible below the sleeve 19.

Side sections 12, 14 are connected to opposite sides of said centerportion 10 by hinges 26,27 having pivot axes parallel to thelongitudinal edges of said center portion. The hinges are located nearthe upper edges of the connected sides of said center portion and sidesections, in such a way that said side sections can be unfolded to aposition where their top surfaces 13, 15 lie in a coplanar relationshipwith said flatbed area 11 of said center portion 10. In this position,the bottom edges of said side sections 12, 14 strike against a pluralityof generally vertical load bearing surfaces disposed on the connectedside of said center portion. The vertical distance between the hingeaxis and the load bearing surfaces creates a supporting moment arm thatallows each side section to be fully cantilevered from said centerportion 10, forming an extended platform.

In this mode of usage racks 34, 35, located underneath the floor panelsof side sections 12,14, are used to create a set of lowered bottom edgeson the side sections. The lower bottom edge increases the supportingmoment arm and thus the load-carrying capacity of the cantilevered sidesections. Cross-structural members 61 link top to bottom frame members62,63 of the rack forming a truss-like structure to provide the desiredbending stiffness to said side sections.

FIG. 1 also shows a standard tent 30 erected on top of said extendedplatform and anchored thereon by means of special adjustable clampassemblies 31 and hold-down ropes 32. These and other ropes 33, that areused to tie down intermediate tent flap anchors, are tied to the racks34, 35 to keep the tent fully taut around its perimeter, the tent poleanchoring method will be described in more details in FIG. 6.

Ground pegs 28 and ropes 29 are used to firmly anchor the extendedplatform to the ground at the four corners of said center portion 10.

Attention is now turned to FIG. 2 and FIG. 3 wherein the presentinvention is shown converted into an open ended U-shaped trailer withflatbed and sidewalls and then with end wall sections added to form anopen-top utility box trailer. Here, the center posts 17 of adjustablepost assembly 16 are retracted away from the ground and slid fullyupward. The upper end portions of said center posts engage holding rings36 located at opposite ends of the hingedly connected side sections12,14 near their free-swinging side. This provides a holding means toselectively and firmly hold said side sections in a substantiallyupright position forming rigid sidewalls. Safety pins 24 are now used toprevent the center post 17 from accidentally sliding down should theclamping means 21 become loose. For this purpose, each of said safetypin is inserted through the nearest hole in the center post that isaccessible right above the sleeve 19.

Racks 34,35 are now found on the outside of the sidewalls and can beused as cargo carriers. The stiffness of the racks impart strength tothe sidewalls in this mode of usage and give them load handlingcapability, they provide longitudinal bending stiffness to the sidewallswhich are only supported at the ends by hinges 26,27 and holding rings36.

FIG. 2 shows the version of an open-ended U-shaped trailer with flatbedand upright sidewalls transporting a load of lumber studs that protrudeout beyond end boundaries of the flatbed area 11. FIG. 3 shows that ofan open-top utility box trailer where end sections 43,44 are slidablyinserted at opposite open ends of the U-shaped trailer to define a cargocarrying volume for the containment of comminuted material such as aload of top soil 37 as shown in the figure. Rings 45 disposed near thetop sides of end sections 43,44 are slid over said center posts bracingthe utility box in the transverse direction and adding rigidity to theentire structure. A shovel 38 is shown attached to the rack illustratingits typical use in this utility trailer mode. A cover 39 is provided onthe open-top to fully enclose the hauled load.

As aforementioned, FIG. 4 shows the trailer in its compactly collapsedversion for highway towing. The side sections 12, 14 are completelyfolded toward the center of the trailer and disposed in a compactlyretracted position where they lie closely adjacent and generallyparallel to the center portion. Latches 40 provide a hold-down means tosecure side sections on top of said center portion 10. In this mode ofusage, racks 34, 35 are found on the top of the trailer ready forcarrying traveling luggage or any general cargo load. Safety pins 24 arealso set in a similar way to that described earlier in FIGS. 2 and 3 toprevent the center posts 17 from dropping down accidentally.

FIG. 5 shows a side view of the compactly collapsed trailer being towedbehind a car. It illustrates the fact that the rear view mirror field ofvision is unobstructed by the trailer body and is only partiallyobstructed by the carried bicycle 41. The low elevation of the cargodeck 42 of the inventive trailer tremendously facilitates the loadingand unloading of the cargo items.

The enlarged view of FIG. 6 best illustrates the technique and devicesof the fastening means that is used to anchor typical standard tentpoles on the trailer platform. The fastening hardware comprises anadjustable clamp assembly 31, a set of tent pole receiving holes 55, aset of holes 56 for passing hold-down ropes through to the underside ofthe platform, and hold-down ropes themselves 32.

Each of said adjustable clamp assembly 31 is formed by: a piece of wire47 bent into a U shape, a metal tab 50 with 2 holes 51 engaging thestraight sections 48 of the U-shaped bent wire 47 where it is free toslide up and down along the body of said piece of wire, and a nut 52attached across the ends of the bent wire closing the loop. A secondring is formed by a second piece of wire bent into a horseshoe shape 46and connected ends to ends onto said metal tab 50, said second ringprovides a means for the attachment of a hold-down rope 32.

The half circular section 49 of said U-shaped bent wire 47 and the metaltab 50 define the adjustable area wherein a standard tent pole 54 isinserted through. A screw 53 engaging the nut 52 pushes on the metal tabto firmly hold the clamp assembly onto the body of the tent pole 54.Said second piece of wire 46 is bent slightly away from the tent pole tofacilitate the attachment of one end of the hold-down rope 32.

During tent erection, the ends of the tent poles 54 that protrudedownward from the tent assembly are first inserted into receiving holes55 provided on the floor panels of the platform. Lower ends of hold-downropes 32 are fed through holes 56, provided on the floor panels, to theunderside of the floor panel where they are strung and tied to the frameof the cargo-racks to keep the ends of the tent poles 54 firmly in placein its receptive holes 55 on the platform. Tent flaps are also anchoredin a similar way by hold-down ropes and the corresponding holes on thefloor panels.

FIG. 7 shows a rack equipped with a screened enclosure 57 used for thestorage of small or loose articles such as hand tools or campingaccessories. The enclosure has door 58 that hinges open on the top sideof the rack to allow convenient access to the storage area in at least 2positions of the side section 12, both the compactly folded and theupright positions. Standard latch mechanisms 59 and lock 60 hold thedoors tightly shut in all modes of usage. The enclosed section of therack has enough bending stiffness such that normal diagonal trussmembers may be omitted.

What is claimed is:
 1. A multipurpose structure convertible betweendifferent utility modes including an open ended U-shaped assembly foruse mainly as a stand-alone load-carrying platform or as a platform on awheeled vehicle comprising: a center portion having a flat surface witha length and a width that defines a flatbed area, a pivotal connectingmeans that connects side sections in a coplanar relationship to saidcenter portion near the upper edges, a plurality of lower load bearingsurfaces disposed on the connected sides of said center portion andlocated at a vertical distance below said connecting means to receiveand support the bottom edges of said side sections, said connectingmeans in combination with said lower load bearing surfaces connect andsupport said side sections in a fully cantilevered manner on oppositesides of said center portion while allowing substantial load-carryingcapacity to said side sections, said center portion having a pluralityof adjustable posts engaging the ground to firmly support and level saidstructure in a stationary and leveled plane above the ground, each ofsaid adjustable posts having an upper end portion that protrudes abovethe flat bed area, a holding means to releasably connect the freelyswinging sides of said side sections to said upper end portions of saidposts to hold said side sections in an upright position forming an openended U-shaped assembly.
 2. The structure as defined in claim 1 whereinsaid side sections are disposed in a compactly retracted position, inthis position said side sections lie closely adjacent and generallyparallel to said center portion, a releasable hold-down means isprovided to secure said side sections to said center portion.
 3. Thestructures as defined in claim 1 in which end sections are removablyattached to opposite open ends of said U-shaped assembly when said sidesections are held in the upright position by said upper end portions ofsaid posts.
 4. The structure as defined in claim 1 further comprising apair of wheels mounted on an axle extended transversely to said U-shapedassembly, a pair of shock absorbing spring assemblies connecting saidstructure to said wheel axle, a towing frame and hitch assembly attachedto said center portion.
 5. The structure as defined in claim 1 whereinsaid center portion is directly mounted on the chassis of a pickuptruck, replacing the body of a cargo tub normally equipped on saidpickup truck.
 6. The structure as defined in claim 1 wherein; saidadjustable posts, supporting and leveling said center portion, comprisefour ground engaging adjustable post assemblies each having a centerpost slidably adjusted in the axial direction inside a sleeve, saidsleeve having releasable clamping means to firmly hold said center postin any axial position, said sleeve being solidly connected to saidcenter portion at each corner of said flatbed area, said connectingmeans to connect said side sections to opposite sides of said centerportion comprises a plurality of hinges, having pivot axes parallel tothe longitudinal edges of said center portion, said holding means,connecting the freely swinging side of said hingedly connected sidesections to said adjustable posts, comprises a pair of holding ringsattached at opposite ends near the freely swinging side of each sidesection, whereby each said center post when sliding upward, engages saidholding ring to hold said side section in an upright position.
 7. Thestructure as defined in claim 2 wherein said side sections comprise aplurality of racks for cargo carrying when said side sections aredisposed in said retracted position; said racks lower the bottom edgesof said side sections when said side sections are configured ascantilevered extensions to said center portion, said lowered bottomedges and the correspondingly disposed load-bearing surfaces on thecenter portion increase the supporting moment arm from said pivotalconnecting means to impart greater strength and load-carrying capacityto said side sections.
 8. The structure as defined in claim 7 whereinsaid cargo carrying racks further comprise a partially or fully enclosedportion with a latched and lockable door that hinges open on the topside of said rack allowing access to the enclosed area.
 9. The structureas defined in claim 1 further comprising fastening means for anchoringstandard tent poles and tent flaps on said extended flatbed area, saidfastening means comprising adjustable clamp assemblies removablyattached to the poles of standard tents to allow the attachment of oneend of hold-down ropes, a first set of holes provided on the floorpanels of said side sections or center portion to receive the ends oftent poles, a second set of holes provided on the floor panels of saidside sections or center portion for passing said hold-down ropes to theunderside of the floor panels where they are tied to anchor points tohold ends of tent poles firmly in place in said first set of holes.